Rewiring

[Alcazar]

QUOTE: Ty Korrigan:<<Hello again... the little red book 'Pas a Pas d'electricite' shows cartoon of a man being electrocuted because his metal pipes are live... and clearly states that it is not permited to earth via these. >>

Aha, now I know the cartoon you mean. (I have the same book).

What it's referring to is the VERY dubious practice of earthing via water pipes, ie: using the water/gas etc pipes as an earth route.

This is obviously a no-no, as they may, or may not themselves be connected to earth, so that any fault will leave them live with potentially fatal consequences

HOWEVER: what it's NOT telling you is not to connect your water/gas etc pipes to AN EXISTING PROPER EARTH via bonding, so that, should the PIPES become live by any accident, the curent will go to earth, and trip whatever trip you have, rather than stay in the pipes and give someone, somewhere a shock.

I hope this clears things up for anyone. It's simply to stop anyone trying to shortcut, and use the water pipes etc as an earth WITHOUT the proper earthing arrangemnets.

I know mine WILL be earth bonded, that's for sure.

Alcazar

 

[Ty Korrigan]

AH! Ta Alk'

[Simon Kennedy]

And let's not forget the question, two messages above:

"Is there a way of avoiding spending the next week with a big drill and massette bashing away?"

Simon

[Ty Korrigan]

You could rent or buy a wall chaser, its a kind of circular saw with two cutting disks that cut a tramway into the wall that you can then knock out by hand without destroying the wall too much.

 

[Mikew]

You must have equipotential bonding to all metal pipes, baths, sinks, metal door frames, conduits etc. A suitable earth must be provided at the main distribution board, complete with a removable link to enable earth tests to be made.

M

[Simon]

Is there enough space in the conduits to shove some plastic ones down them?

Simon

[Simon Kennedy]

Simon, that is a really good idea.

If only. The metal conduits are pretty narrow, about 20mm diametre, so no, I don't think I can shove anything down there.

Simon K

[Gyn_Paul]

I can confirm that Consuel WILL fail you on an installation with kit which only has a 'CE' symbol on it. I had wall-mounted room convector heaters fitted without a NF mark and that was enough for the obligatory sucking of teeth and shaking of the head to begin.!

p

[VJ]

(Notwithstanding the entry of water into the house via plastic pipes, (which is, incidentally, the same as in the UK, in all but the very oldest houses), wouldn't it be better to have pipework connected to ground? Then, should a live wire inadvertently make contact with a pipe, the RCD/mcb will imediately trip, and even should a person be ALSO in contact with the pipe at the same time, Ohm's Law would show that the proportion of current flowing through that person to ground, would probably not even be noticed, (around 9 MILLIONTHS of an amp for a wet through person with a resistance of around 10k Ohms which is VERY low, and a household earth of 30 Ohms which is very high).

Sorry to be a bit pedantic, but I STILL believe a decent earth to metal bits is vital.)

Alcazar

The above is spot on Alcazar (so that no potential difference exists between metal work) and if there are circuits used for external sockets ect then use a 10 ma RCD and PLEASE do not start on nusance tripping better to have a protected circuit than a corpse

[Alan Zoff]

Regulations apart, is it possible/practical to wire a new consumer unit to an existing live fuse-box which has a main cut-out switch, as a temporary measure?

[Nick Trollope]

[quote]Regulations apart, is it possible/practical to wire a new consumer unit to an existing live fuse-box which has a main cut-out switch, as a temporary measure?[/quote]

Regulations apart, of course it is. Although I can't see why you would want to wire it to the "output" of the fusebox, rather than the input. If it was done properly, then it would comply, I guess, as you are allowed more than 1 tableau.

 

[Alan Zoff]

Thanks Nick.

I would prefer to wire new unit directly to the input but I assumed I would have to involve the EDF bods for that. Or is there a way for me to isolate power from input in order to make a direct hook-up to new consumer unit myself?

Alan

[Nick Trollope]

[quote]Thanks Nick. I would prefer to wire new unit directly to the input but I assumed I would have to involve the EDF bods for that. Or is there a way for me to isolate power from input in order to make a...[/quote]

Ah! Are we talking about the EDF main breaker - with "test" button & an on & off button, and seals on the input side, or something older?

If it is an EDF breaker, then you are allowed access to the switched side, but not to the input side, which should be sealed. If your installation is old, then get it changed before you do anything. It should not be necessary (or possible) for you to wire anything "live".

Check again, and/or call an Electrician!

 

[Alan Zoff]

Thanks again Nick

Am sending this from England so don't have the equipment in front of me and can't quite visualise it exactly till I get back there in fortnight's time. But yes there is a test button next to fuse box. [The French vendor had some new wiring done by an electrician about 10 years ago when cellar was kitted out with a boiler and washing machine and may have installed an EDF test switch then. However, the wiring to the main rooms is anything but modern and in some cases downright dangerous - no earth pins in sockets (or where there are, no earth wires), thin 2-core lighting flex running between main power sockets (sometimes via lights), exposed live terminals, no earth cross-bonding of metalwork, etc. So I plan to sort out a number of DIY improvements till I have funds to get electrician involved. It's for my use only at present and got to be safer than what's there now. I have a spanking new consumer unit so thought I might as well connect that up while I'm at it.]

If I have understood you correctly, seems as if I should be able to isolate power from the test switch unit and connect my new consumer unit directly to it, without having to go via fuse box.

Cheers.

Alan

[Ty Korrigan]

Hello, A question about main switches....

I have 3 phase overhead 30amp supply which goes to EDF's 500mA RCD/earth leakage trip/ main switch.

I am renovating an outbuilding  which will require the same 3 phase supply to a new fuse board.

Question is...

Is there a requirement for one main switch to each building as in the U.K or is it O.K to have 3 separate 30mA RCDs/ earth leakage trips on each of the 3 phases?

[Nick Trollope]

[quote]Hello, A question about main switches.... I have 3 phase overhead 30amp supply which goes to EDF's 500mA RCD/earth leakage trip/ main switch. I am renovating an outbuilding which will require the s...[/quote]

Yes, you can have seperate (i.e. 3-off monophase DD's, rather than 1 3-phase DD, I assume that this is what you mean). Why it is legit, I don't know, but it is!

Alan - just assure me that you are not proposing to use a UK consumer unit (which are neither safe not legal in France)!

 

[Ianhaycox]

Nick, dumb question but, are you sure you mean DD not ID ? I thought an ID was needed for earth leakage etc.

[Alan Zoff]

Nick

Damn! There had to be a catch.  I have a spanking new UK unit kitted out with 12 new breakers.

What's the safety issue? Aren't we using same power?

[Alcazar]

AFAIK, the safety unit is that in the UK only the live (phase) is interrupted by circuit breakers, whereas in France, both live AND neutral are.

Use French stuff, it'll save a lot of heartache.

Alcazar

[Nick Trollope]

[quote]Nick, dumb question but, are you sure you mean DD not ID ? I thought an ID was needed for earth leakage etc.[/quote]

Of course I did. Well spotted. Ahem.

Alan. NO NO NO etc. Don't use a UK consumer unit. There is no way it's use is either legal or safe. See earlier in the thread, but as Alcazar points out, it will be a live-only switch. There is no real definition between live and neutral in France so ALL breakers, appliance switches and the like MUST be double-pole.

Sorry.

 

[Alan Zoff]

Thanks Nick (and Alcazar).

I will of course follow advice but must say I'm a bit baffled. Whatever the French system is, all I intended doing was the same as in UK - connecting live to live, neutral to neutral using similar single phase power supply. Why is it safe in England with the cut-out on the live (phase) side only and unsafe in France?

Unless of course they are less particular about how they wire up their sockets but, as in the UK wiring I have done, I was going to double check that all outlets were correctly wired for polarity before applying power. (The appliances sold in France must surely be correctly wired as they wouldn't be able to export anything to UK.)

I may be missing something more technical - or perhaps very basic! - but seems to me the only real risk is that someone else might come along later and assume that the system had double pole cut-outs - and therefore not bother to think about polarity when adding new sockets. 

[Nick Trollope]

[quote]Thanks Nick (and Alcazar). I will of course follow advice but must say I'm a bit baffled. Whatever the French system is, all I intended doing was the same as in UK - connecting live to live, neutral ...[/quote]

OK

As you may be aware, in the UK, the Neutral feed is earthed in the substation and the Live wire is regarded as AC "positive" with respect to it. This also applies in France, but, it is quite possible that the N & L wires are reversed between yourself and the SS (in the past, and now too, I suspect, as the supply was "AC", then both wires were regarded as the same thing, as would be the case in an isolated power supply in a radio, for example). By switching both sides, you guarantee to disconnect the live.

They are also less particular about how they (Fr system) wire up sockets, and 2-pin non-polarised sockets are still used in lighting circuits (of course, it doesn't matter which way round it is wired, in an AC system, if you switch both sides....!!!). The UK obsession with "Live (red) to the right" goes back to the DC days and the fact that UK plug tops are fused (although a fuse in the Neutral will work as well....).

There are also (I believe, and in some parts of France) systems like the American one of 2 115V supplies, where both wires are "live" and the centre of the SS transformer is earthed. But my degrees are in Electronics - and we never touched "electricity", so what do I know...!!!!

 

[Alan Zoff]

Thanks Nick for the very full reply.

Sorry to have made you work so hard with this one!

Alan

[VJ]

Alan this may help

If only the line is fused when it blows /trips then the appliance, fitting, light ,whatever, is disconnected from line but the neutral which is effectively the earthed centre tapping of the generator is still connected.

Double pole fusing was stopped in the 50's as if a neutral fuse operated then the appliance would still have the live connected and is considered dangerous so particular attention needs to be given to polarity and in fact even with DP mcb it is not good practice to be switching neutrals say on a lighting circuit

One problem with single pole MCB is when using a RCB on main line as is normal then if you are working on a circuit with the breaker off the neutral is still connected which if you earth will send an amperage in parrallel to the neutral thereby tripping out the RCB

Not much fun if you are in a roof with a light on

I beleive it is better always to fit Double pole breakers and in fact the houses I have wired in the UK I have fitted double pole breakers but adopted the only swtching of the line

[Alan Zoff]

Thanks VJ. 

Presumably all of what you say applies equally on each side of the Channel. (UK electricity authorities/consumer unit manufacturers take note.)

The stuff you can learn on a Living France website!

Alan